Material handling apparatus for delivering or retrieving items

摘要

A method and apparatus are provided for sorting or retrieving items to/from a plurality of destinations areas. The items are loaded onto one of a plurality of independently controlled delivery vehicles. The delivery vehicles follow a track that guides the delivery vehicles to/from the destination areas, which are positioned along the track. Once at the appropriate destination area, an item is transferred between the delivery vehicle and the destination area.

主权项

1. A material handling system, comprising:
a plurality of destination areas; a plurality of delivery vehicles for delivering items; a track for guiding the delivery vehicles vertically and horizontally, wherein the destination areas are positioned along the track so that items can be transferred between the delivery vehicles and the destination areas, wherein during operation, one or more of the delivery vehicles are located on the track; a traffic controller for controlling the operation of the vehicles as the vehicles deliver items to the bins, wherein the traffic controller monitors the positions of the vehicles located on the track and calculates a safe distance for each vehicle and communicates the safe distance to the vehicles, wherein the safe distance for a vehicle corresponds to the distance that the vehicle can advance without interfering with another vehicle on the track; wherein the delivery vehicles receive the safe distance signals from the traffic controller and advance along the track a distance corresponding to the safe distance; and wherein the traffic controller iteratively calculates safe distances for each vehicle as the vehicles move along the track and the vehicles advance along the track a distance no further than the safe distance until receiving a subsequent safe distance from the traffic controller.